I got this email a few days ago with the subject line
Why do I want to listen to your podcast??
and the content of
I just heard you say that on your podcast.
Because the only place I can listen to stuff I am interested in is on your podcast. I am not interacting with you but if feels like a conversation. It is a conversation that I cannot have with anyone I know.
I usually learn something / I don't always agree with everything / there are things I would like to add or change / it is interesting to me / there is not a single soul in my area that talks like you and the lady you have in your podcasts - it makes me feel like I am not the 'lone ranger'
Keep on keepin on 
I have to admit that I not only see the point, but it puts a bit of wind in my sails to do this.
Helen Atthowe stopped by to help me do some video carving. And I shared this with her. She was clear that she was not going to do podcasts on this trip because she didn't have time. But after telling her about this, we did one or two anyway.
I shared it with Jocelyn and she liked it too. So now she has been taking notes on a big now podcast.
I did a roundtable podcast with four people after a presentation I gave, and one of them (Caleb) said something similar.
I still don't fully understand podcast stuff, and am amazed that so many people want to hear me talk. I still have this feeling that it isn't going to last very long, but ... well ... for now it seems like people want to hear this stuff. And notes like this make me think it a worthwhile effort.